846 C. SKOTTSBERG 



branches 0.92 and 1.12m long and 4.6 and 2.7 cm thick, respectively, with 

 subumbellate innovations, 7 and 6 in number, respectively. This is the plant 

 illustrated on PI. 17: i of no. 7 in this volume; it was an exception from the 

 rule, also observed by this species, that only 2 or 3 innovations are formed. 

 End of February they were in full growth. The nearest relative is R. evenia, 

 and like this it occurs as an epiphyte on Dicksonia and also on Lophosoria, but 

 as a rule it is not epiphytic. Flowers Jan. — Feb. Sterile specimens were seen in 

 the forest, an unsuitable habitat for a Robinsonia\ stem thin, with long internodes, 

 leaves long, flaccid. 



Robinsonia thurifera Dene, "Resino macho" ( = male r.). PI. 6'j . Endemic on 

 Masatierra and very rare, only found on the slope of Cordon Chifladores above Puerto 

 Frances, 350 — 450 m, and near Portezuelo de Villagra, 550 — 600 m. Largest of 

 the genus, up to 5 or even 6 m tall with a trunk 5 — 10 cm thick; the largest tree 

 seen by us had a stem 1.53 m long and 18.5 cm thick. Large specimens 

 had 9 generations of branches. Often trichotomous. Flowers later than any 

 other tree or shrub in the islands; bloom at its peak in March — April, when 

 also the innovations are well developed. On March 15 a comparison was made 

 with R. gayana (also see above); in R. thurifera, the flowering shoots still bore 

 all their leaves, only the oldest ones turning yellow, and the innovations were 

 less advanced. They did not, as in R. gayana, begin with a number of re- 

 duced leaves. A single epiphytic plant was observed, growing on Blechniini 

 cycadjfoliiwt. 



Robinsonia gracilis Dene, "Resinillo". Endemic on Masatierra and inhabiting 

 the same kind of stations as the former, but more common and ranging from the 

 ridge between the Piedra Agujereada and Laura valleys to Cordon Salsipuedes. 

 Not seen by us below 500 m, but reported from 400 and 450 (Skottsb. ig. 362). 

 Once numerous seedlings were found growing on Dicksonia (Fig. 12 d, e), and on 

 one occasion a flowering specimen on Blechmun cycadifolitini. It is possible that 

 the large plant mentioned below had germinated on the base of a Dicksonia, 

 against which its stem was tightly pressed, later sending roots into the soil, but 

 in other cases I had no reason to suspect that it had started as an epiphyte. 

 Mostly of lower stature than its congeners and easily recognized by the small, 

 narrow, rather stiff leaves, different in shape from the juvenile ones seen in Fig. 12. 

 PI. 68: I shows a typical specimen, i — 2 m tall with a main stem 20 — 50 cm long 

 and 5 — 8 cm thick. A plant 1.6 m tall had 16 generations of branches. One 

 exceptionally large specimen measured 4 m, with the trunk 17 cm thick. Young 

 bark greenish, later gray. Seen with resting leaf buds of the usual type in August, 

 with flowering heads from the middle of December to the end of January. The 

 leaves stay on longer than in the other species, but are gradually shed up to 

 the corymb before the winter. Towards the end of December the innovations, 

 2 — 4 in number, are about i cm long; in April they measured several cm and 

 the lower leaves had been shed; the first few are of smaller size and short-lived. 

 The apex was still growing and new leaves formed. 



Symphyochaeta macrocephala (Dene) Skottsb., "Incensio" (a corruption for 

 incienso: the resin was once used not only as medicine, but also as incense). Also 



